1 files changed, 57 insertions, 17 deletions

diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index ec6635dc50f9..0075e43ffea6 100644
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -84,14 +84,26 @@ out:
 	return res;
 }
 
-/**
- * ext4_generate_encryption_key() - generates an encryption key
- * @inode: The inode to generate the encryption key for.
- */
-int ext4_generate_encryption_key(struct inode *inode)
+void ext4_free_encryption_info(struct inode *inode)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_crypt_info *ci = ei->i_crypt_info;
+
+	if (!ci)
+		return;
+
+	if (ci->ci_keyring_key)
+		key_put(ci->ci_keyring_key);
+	crypto_free_ablkcipher(ci->ci_ctfm);
+	memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
+	kfree(ci);
+	ei->i_crypt_info = NULL;
+}
+
+int _ext4_get_encryption_info(struct inode *inode)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
+	struct ext4_crypt_info *crypt_info;
 	char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
 				 (EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
 	struct key *keyring_key = NULL;
@@ -99,18 +111,40 @@ int ext4_generate_encryption_key(struct inode *inode)
 	struct ext4_encryption_context ctx;
 	struct user_key_payload *ukp;
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
-				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
-				 &ctx, sizeof(ctx));
+	int res;
 
-	if (res != sizeof(ctx)) {
-		if (res > 0)
-			res = -EINVAL;
-		goto out;
+	if (ei->i_crypt_info) {
+		if (!ei->i_crypt_info->ci_keyring_key ||
+		    key_validate(ei->i_crypt_info->ci_keyring_key) == 0)
+			return 0;
+		ext4_free_encryption_info(inode);
 	}
+
+	res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+				 &ctx, sizeof(ctx));
+	if (res < 0) {
+		if (!DUMMY_ENCRYPTION_ENABLED(sbi))
+			return res;
+		ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
+		ctx.filenames_encryption_mode =
+			EXT4_ENCRYPTION_MODE_AES_256_CTS;
+		ctx.flags = 0;
+	} else if (res != sizeof(ctx))
+		return -EINVAL;
 	res = 0;
 
+	crypt_info = kmalloc(sizeof(struct ext4_crypt_info), GFP_KERNEL);
+	if (!crypt_info)
+		return -ENOMEM;
+
 	ei->i_crypt_policy_flags = ctx.flags;
+	crypt_info->ci_flags = ctx.flags;
+	crypt_info->ci_data_mode = ctx.contents_encryption_mode;
+	crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
+	crypt_info->ci_ctfm = NULL;
+	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
+	       sizeof(crypt_info->ci_master_key));
 	if (S_ISREG(inode->i_mode))
 		crypt_info->ci_mode = ctx.contents_encryption_mode;
 	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
@@ -151,17 +185,23 @@ int ext4_generate_encryption_key(struct inode *inode)
 	res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
 				  crypt_info->ci_raw);
 out:
+	if (res < 0) {
+		if (res == -ENOKEY)
+			res = 0;
+		kfree(crypt_info);
+	} else {
+		ei->i_crypt_info = crypt_info;
+		crypt_info->ci_keyring_key = keyring_key;
+		keyring_key = NULL;
+	}
 	if (keyring_key)
 		key_put(keyring_key);
-	if (res < 0)
-		crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
 	return res;
 }
 
 int ext4_has_encryption_key(struct inode *inode)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
 
-	return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID);
+	return (ei->i_crypt_info != NULL);
 }